<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:1b9d7a2e-fcad-4fc1-a669-632860fb32c8,g:fa86daf1-c4a6-483d-8a6f-1efb203cf47f-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.protolabs.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="prlb-20250930.xsd#ConsolidatedBalanceSheets"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_94e9aac6-4579-43a4-8301-b8673fab06f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_AssetsCurrent_94e9aac6-4579-43a4-8301-b8673fab06f2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_729de6bb-779c-4fca-8ff7-dee4dd2a040a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_729de6bb-779c-4fca-8ff7-dee4dd2a040a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_d43207ce-a0db-4bc4-bbb5-9b75d3da2770" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_Goodwill_d43207ce-a0db-4bc4-bbb5-9b75d3da2770" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_907fda7b-8657-48a4-a2a3-a523e527aec9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_907fda7b-8657-48a4-a2a3-a523e527aec9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesNoncurrent_72f827e0-0c8d-4e51-bb36-fb0990f5e241" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketableSecuritiesNoncurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_MarketableSecuritiesNoncurrent_72f827e0-0c8d-4e51-bb36-fb0990f5e241" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsNet_ad9c8506-5bf8-43e0-99d8-7ca5329c94f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherIntangibleAssetsNet"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_OtherIntangibleAssetsNet_ad9c8506-5bf8-43e0-99d8-7ca5329c94f0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseRightOfUseAsset_e888aa25-c446-4c0c-a304-ec489182fad7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseRightOfUseAsset"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_FinanceLeaseRightOfUseAsset_e888aa25-c446-4c0c-a304-ec489182fad7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_a4e83122-4c70-4905-9516-efaeb81e076d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:calculationArc order="8" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_732d66a2-fad0-4f1b-9858-092e6bb4f39d" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_a4e83122-4c70-4905-9516-efaeb81e076d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_79f3d196-d89d-4015-a2a6-3c308f9ce613" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketableSecuritiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_79f3d196-d89d-4015-a2a6-3c308f9ce613" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_6d17b200-16d2-4b56-ac13-521870abb91c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryNet"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:to="loc_us-gaap_InventoryNet_6d17b200-16d2-4b56-ac13-521870abb91c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_fb6b6177-8f7b-4fbe-b3ea-8a63291f8736" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_fb6b6177-8f7b-4fbe-b3ea-8a63291f8736" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_2bf18fe5-5d77-421c-a094-03a4b902b2fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_2bf18fe5-5d77-421c-a094-03a4b902b2fe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesReceivable_1ec8b2e3-7890-4c47-9d0d-a335076fe0a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesReceivable"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:to="loc_us-gaap_IncomeTaxesReceivable_1ec8b2e3-7890-4c47-9d0d-a335076fe0a1" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_92d32b63-4069-42f3-b37b-c06072eee225" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_14a4a71a-c34e-4942-9536-fd856fa246aa" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_92d32b63-4069-42f3-b37b-c06072eee225" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_1f4fa9ed-4479-45a9-9e1f-ca43a64c1bd2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_31b85cf0-6d25-4455-8703-8162d7559f6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_1f4fa9ed-4479-45a9-9e1f-ca43a64c1bd2" xlink:to="loc_us-gaap_Liabilities_31b85cf0-6d25-4455-8703-8162d7559f6d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_c030e951-e1f8-4ee9-8c20-9883cc28dcbe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_1f4fa9ed-4479-45a9-9e1f-ca43a64c1bd2" xlink:to="loc_us-gaap_StockholdersEquity_c030e951-e1f8-4ee9-8c20-9883cc28dcbe" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_18c4364a-f54a-4c8a-bdf8-7d6a2d7d8f64" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_caa2199a-ba76-4086-9473-85398e772739" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_18c4364a-f54a-4c8a-bdf8-7d6a2d7d8f64" xlink:to="loc_us-gaap_LiabilitiesCurrent_caa2199a-ba76-4086-9473-85398e772739" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_a5072e6e-00f7-40bf-acb2-c1dfa8a2468a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_18c4364a-f54a-4c8a-bdf8-7d6a2d7d8f64" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_a5072e6e-00f7-40bf-acb2-c1dfa8a2468a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_65a88866-ec65-4f84-87fc-2f9693bd3a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_18c4364a-f54a-4c8a-bdf8-7d6a2d7d8f64" xlink:to="loc_us-gaap_FinanceLeaseLiabilityNoncurrent_65a88866-ec65-4f84-87fc-2f9693bd3a8a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_2fac86b4-9bed-4c20-b939-160bf0c74720" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_18c4364a-f54a-4c8a-bdf8-7d6a2d7d8f64" xlink:to="loc_us-gaap_OperatingLeaseLiabilityNoncurrent_2fac86b4-9bed-4c20-b939-160bf0c74720" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_e0b548b6-02db-43d1-a372-a16bf93faddb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_18c4364a-f54a-4c8a-bdf8-7d6a2d7d8f64" xlink:to="loc_us-gaap_DeferredIncomeTaxLiabilitiesNet_e0b548b6-02db-43d1-a372-a16bf93faddb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_9a14799a-84e6-464e-be0c-b9b26de41f3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesAndOtherLiabilities_2b9d1a5e-bc14-4d6f-8983-7b00e87b4174" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccruedLiabilitiesAndOtherLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_9a14799a-84e6-464e-be0c-b9b26de41f3b" xlink:to="loc_us-gaap_AccruedLiabilitiesAndOtherLiabilities_2b9d1a5e-bc14-4d6f-8983-7b00e87b4174" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilityCurrent_6184869f-e231-42fa-9058-febe6d9f9363" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseLiabilityCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_9a14799a-84e6-464e-be0c-b9b26de41f3b" xlink:to="loc_us-gaap_OperatingLeaseLiabilityCurrent_6184869f-e231-42fa-9058-febe6d9f9363" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeaseLiabilityCurrent_04df90c5-fd33-4c38-9162-2a75d8c06098" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeaseLiabilityCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_9a14799a-84e6-464e-be0c-b9b26de41f3b" xlink:to="loc_us-gaap_FinanceLeaseLiabilityCurrent_04df90c5-fd33-4c38-9162-2a75d8c06098" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_5025f12b-84a8-4d81-bdff-0acfde8b362e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_9a14799a-84e6-464e-be0c-b9b26de41f3b" xlink:to="loc_us-gaap_EmployeeRelatedLiabilitiesCurrent_5025f12b-84a8-4d81-bdff-0acfde8b362e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableCurrent_03ecfc93-edf4-4727-a948-2f78566c5ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_9a14799a-84e6-464e-be0c-b9b26de41f3b" xlink:to="loc_us-gaap_AccountsPayableCurrent_03ecfc93-edf4-4727-a948-2f78566c5ce8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_e7bc0cd6-dcde-4e34-a69b-69a7affff289" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_f81387fe-f7fb-4ce8-a8d6-bf022a6e56f8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_e7bc0cd6-dcde-4e34-a69b-69a7affff289" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_f81387fe-f7fb-4ce8-a8d6-bf022a6e56f8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_76b2405b-867a-4e32-8508-20251f0bd201" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_e7bc0cd6-dcde-4e34-a69b-69a7affff289" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_76b2405b-867a-4e32-8508-20251f0bd201" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_3c5b10b1-e1eb-4c6c-87c3-805807c755e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_e7bc0cd6-dcde-4e34-a69b-69a7affff289" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_3c5b10b1-e1eb-4c6c-87c3-805807c755e3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_48e2708c-204e-468f-8867-a175583b46ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_e7bc0cd6-dcde-4e34-a69b-69a7affff289" xlink:to="loc_us-gaap_CommonStockValue_48e2708c-204e-468f-8867-a175583b46ac" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_9f22bdf7-eeda-4a93-9e4b-550a22e178a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_e7bc0cd6-dcde-4e34-a69b-69a7affff289" xlink:to="loc_us-gaap_PreferredStockValue_9f22bdf7-eeda-4a93-9e4b-550a22e178a7" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/ConsolidatedStatementsofComprehensiveIncome" xlink:type="simple" xlink:href="prlb-20250930.xsd#ConsolidatedStatementsofComprehensiveIncome"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/ConsolidatedStatementsofComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_e24e2161-d16a-4116-b293-fd0714447254" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_bbb606c1-adba-492f-8b05-7bc4ea58dc6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_e24e2161-d16a-4116-b293-fd0714447254" xlink:to="loc_us-gaap_OperatingExpenses_bbb606c1-adba-492f-8b05-7bc4ea58dc6e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_f6e3804f-6ac2-4d2c-b17b-5c7fba8ef00e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_e24e2161-d16a-4116-b293-fd0714447254" xlink:to="loc_us-gaap_GrossProfit_f6e3804f-6ac2-4d2c-b17b-5c7fba8ef00e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_a5317eea-8a39-41b7-835c-642d9dacb0d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_9e932cb9-0114-4611-a832-16335a7f68f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_a5317eea-8a39-41b7-835c-642d9dacb0d5" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_9e932cb9-0114-4611-a832-16335a7f68f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_8d59d398-b677-4313-9302-508b95f40df0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_a5317eea-8a39-41b7-835c-642d9dacb0d5" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_8d59d398-b677-4313-9302-508b95f40df0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_a302d0e0-b9a2-4f1b-9596-ce64079b4020" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_100721d0-24e7-44c0-b6f6-ccbe192b4c5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_a302d0e0-b9a2-4f1b-9596-ce64079b4020" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_100721d0-24e7-44c0-b6f6-ccbe192b4c5e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_b410f7fc-685c-4954-9c69-ea520d5fef6b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_a302d0e0-b9a2-4f1b-9596-ce64079b4020" xlink:to="loc_us-gaap_OperatingIncomeLoss_b410f7fc-685c-4954-9c69-ea520d5fef6b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_74b4b3f8-0cfa-454f-9a8a-36f20059af9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_b9247ebf-ee31-4019-be14-92a4c5a56dc2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_74b4b3f8-0cfa-454f-9a8a-36f20059af9a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_b9247ebf-ee31-4019-be14-92a4c5a56dc2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_f6a4a9e3-4506-4518-b9e2-d031d742e654" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_74b4b3f8-0cfa-454f-9a8a-36f20059af9a" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_f6a4a9e3-4506-4518-b9e2-d031d742e654" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_fa900e38-72bf-4afd-aacd-33dd33ee624e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_faff8481-ad18-446b-8e06-5fdc73955977" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_fa900e38-72bf-4afd-aacd-33dd33ee624e" xlink:to="loc_us-gaap_SellingAndMarketingExpense_faff8481-ad18-446b-8e06-5fdc73955977" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_a162357e-5a62-41ee-94f8-bc9572a10cf9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_fa900e38-72bf-4afd-aacd-33dd33ee624e" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_a162357e-5a62-41ee-94f8-bc9572a10cf9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_9312ab5c-3da6-4db6-8297-58051a53d742" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_fa900e38-72bf-4afd-aacd-33dd33ee624e" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_9312ab5c-3da6-4db6-8297-58051a53d742" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_e06366d3-18db-4465-b45d-fdbe24d41bd9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfBusiness"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingExpenses_fa900e38-72bf-4afd-aacd-33dd33ee624e" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_e06366d3-18db-4465-b45d-fdbe24d41bd9" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="prlb-20250930.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2037c655-e4af-4090-8bcb-a531ec91fc65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_91b734ba-3be6-4017-80d4-d7e2406f7f0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2037c655-e4af-4090-8bcb-a531ec91fc65" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_91b734ba-3be6-4017-80d4-d7e2406f7f0d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_62ebc288-d8f1-4add-80ed-b0f485e11533" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2037c655-e4af-4090-8bcb-a531ec91fc65" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_62ebc288-d8f1-4add-80ed-b0f485e11533" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinanceLeasePrincipalPayments_36ad080c-c326-41bf-bcd3-8ea829b9c1f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinanceLeasePrincipalPayments"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2037c655-e4af-4090-8bcb-a531ec91fc65" xlink:to="loc_us-gaap_FinanceLeasePrincipalPayments_36ad080c-c326-41bf-bcd3-8ea829b9c1f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_9e6bb974-8312-4a58-aef9-6d6971f86a3c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_2037c655-e4af-4090-8bcb-a531ec91fc65" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_9e6bb974-8312-4a58-aef9-6d6971f86a3c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_a04f4fe7-b7b1-4320-99c0-ec4c1ebdb8df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_ef554127-dbd3-4508-92e1-c9789a7496d0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfProductiveAssets"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_a04f4fe7-b7b1-4320-99c0-ec4c1ebdb8df" xlink:to="loc_us-gaap_ProceedsFromSaleOfProductiveAssets_ef554127-dbd3-4508-92e1-c9789a7496d0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_db08a192-b599-4ed3-a0c1-dfbc47aa4899" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_a04f4fe7-b7b1-4320-99c0-ec4c1ebdb8df" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_db08a192-b599-4ed3-a0c1-dfbc47aa4899" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_645758d9-0533-40bc-b854-57fb462c594b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_a04f4fe7-b7b1-4320-99c0-ec4c1ebdb8df" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_645758d9-0533-40bc-b854-57fb462c594b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_f0d966ad-982f-4f1e-abd6-082628d1be6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_a04f4fe7-b7b1-4320-99c0-ec4c1ebdb8df" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_f0d966ad-982f-4f1e-abd6-082628d1be6e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cd86600e-68a5-4136-93c1-8692998d89d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_fcb85afa-d25a-469c-8862-f504a273c34c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cd86600e-68a5-4136-93c1-8692998d89d4" xlink:to="loc_us-gaap_EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations_fcb85afa-d25a-469c-8862-f504a273c34c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_11538beb-8d03-42bd-9ae5-d0bac7dc03a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cd86600e-68a5-4136-93c1-8692998d89d4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_11538beb-8d03-42bd-9ae5-d0bac7dc03a7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_5d1918f0-4749-49b9-888a-efd490c47cbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cd86600e-68a5-4136-93c1-8692998d89d4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_5d1918f0-4749-49b9-888a-efd490c47cbd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_84dc6df2-2434-4bd1-b334-45f66449008c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_cd86600e-68a5-4136-93c1-8692998d89d4" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_84dc6df2-2434-4bd1-b334-45f66449008c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_ccf2a1fd-552f-461f-b6aa-a413258a839f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_ccf2a1fd-552f-461f-b6aa-a413258a839f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_db8391a5-6509-4f78-b2e5-81d91e3b0aec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_db8391a5-6509-4f78-b2e5-81d91e3b0aec" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_6166f649-6187-424a-9cee-ba5de5be06cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_6166f649-6187-424a-9cee-ba5de5be06cb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayable_950f8fc0-0df8-413f-81ca-fc20109248f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayable"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayable_950f8fc0-0df8-413f-81ca-fc20109248f3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisposalGroupNotDiscontinuedOperationLossGainOnWriteDown_74b4cd8c-7d1b-4dbd-9bb8-efd5e3890036" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisposalGroupNotDiscontinuedOperationLossGainOnWriteDown"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_DisposalGroupNotDiscontinuedOperationLossGainOnWriteDown_74b4cd8c-7d1b-4dbd-9bb8-efd5e3890036" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_bb40b361-9dd9-4d84-8691-bdddeb375b3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_bb40b361-9dd9-4d84-8691-bdddeb375b3b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_5cfa1bdb-edd3-441c-9d59-44c4af142f55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="7" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_ShareBasedCompensation_5cfa1bdb-edd3-441c-9d59-44c4af142f55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_1a833946-4427-417e-a277-1e3f174e7938" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_GainLossOnSaleOfPropertyPlantEquipment_1a833946-4427-417e-a277-1e3f174e7938" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccretionExpense_976c38c0-161e-4034-880c-a0b222391527" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccretionExpense"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_AccretionExpense_976c38c0-161e-4034-880c-a0b222391527" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_939c308f-95b5-4ae8-9c6d-7aaee5ea5360" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="10" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_NetIncomeLoss_939c308f-95b5-4ae8-9c6d-7aaee5ea5360" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_ad5689fc-1019-41b0-966f-1b9d6271f65b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement"/>
    <link:calculationArc order="11" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_ad5689fc-1019-41b0-966f-1b9d6271f65b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_a0d0d3da-7518-4fb0-9bf4-21dadceeaa12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets"/>
    <link:calculationArc order="12" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_a0d0d3da-7518-4fb0-9bf4-21dadceeaa12" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_d6a7d1ea-0e56-4b53-8be2-863b59d48d42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="13" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_d6a7d1ea-0e56-4b53-8be2-863b59d48d42" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_cf8c5170-6587-4548-9ee5-0c9f6e2b1ac2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable"/>
    <link:calculationArc order="14" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_IncreaseDecreaseInAccruedIncomeTaxesPayable_cf8c5170-6587-4548-9ee5-0c9f6e2b1ac2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_62b4880f-bb2e-48f1-b2bb-7848abb6267d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf"/>
    <link:calculationArc order="15" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_278d8a8e-7504-4e03-a175-f82160ec5f81" xlink:to="loc_us-gaap_ImpairmentOfLongLivedAssetsToBeDisposedOf_62b4880f-bb2e-48f1-b2bb-7848abb6267d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/NetIncomeperCommonShareScheduleofComputationOfBasicandDilutedNetIncomePerShareDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#NetIncomeperCommonShareScheduleofComputationOfBasicandDilutedNetIncomePerShareDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/NetIncomeperCommonShareScheduleofComputationOfBasicandDilutedNetIncomePerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_91957a08-b480-43ca-af46-0b38bd2c12ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_22e95ec8-0e6f-4166-b61e-47d1881390e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_91957a08-b480-43ca-af46-0b38bd2c12ce" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_22e95ec8-0e6f-4166-b61e-47d1881390e6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_7050181f-df20-423c-a6f3-9b98732e25a1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_91957a08-b480-43ca-af46-0b38bd2c12ce" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_7050181f-df20-423c-a6f3-9b98732e25a1" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsOtherThanGoodwillDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsOtherThanGoodwillDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsOtherThanGoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_247ad393-9db3-41ff-9bf2-1a8248a8b3d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_76dece84-99b9-4def-901e-4ee80e640ab5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_247ad393-9db3-41ff-9bf2-1a8248a8b3d8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_76dece84-99b9-4def-901e-4ee80e640ab5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_ec6d9461-7aa8-4e5b-880d-a41fda8397ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_247ad393-9db3-41ff-9bf2-1a8248a8b3d8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_ec6d9461-7aa8-4e5b-880d-a41fda8397ac" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofAggregatedAmortizationExpenseDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#GoodwillandOtherIntangibleAssetsScheduleofAggregatedAmortizationExpenseDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/GoodwillandOtherIntangibleAssetsScheduleofAggregatedAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_4de3c9d8-c24c-479c-9322-4a35704fb75a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_4de3c9d8-c24c-479c-9322-4a35704fb75a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_1ac32cd8-f70c-4629-9593-d09ae5fe3c3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_1ac32cd8-f70c-4629-9593-d09ae5fe3c3f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_4a3b7160-fbdf-4aea-b812-a19a8bd328aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear_4a3b7160-fbdf-4aea-b812-a19a8bd328aa" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_prlb_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour_7bfd0a42-bff2-48c4-bcf8-4af073b0a738" xlink:href="prlb-20250930.xsd#prlb_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:to="loc_prlb_FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour_7bfd0a42-bff2-48c4-bcf8-4af073b0a738" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_068a0c69-96bc-4f08-8433-15d4a70ac10b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_068a0c69-96bc-4f08-8433-15d4a70ac10b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_e813bc0c-a29d-4973-a0f7-c2560ad57b49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsNet_c6b63933-8ab2-413c-a42b-0718f4d1a810" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_e813bc0c-a29d-4973-a0f7-c2560ad57b49" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/FairValueMeasurementsDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#FairValueMeasurementsDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_a76649c0-1f39-4c74-a165-f66b441c2540" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_bf53b525-ee2c-44fc-ae94-12f875f483e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_a76649c0-1f39-4c74-a165-f66b441c2540" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_bf53b525-ee2c-44fc-ae94-12f875f483e0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_e054315b-a875-4d47-82b2-0ca9a3857c1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_a76649c0-1f39-4c74-a165-f66b441c2540" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_e054315b-a875-4d47-82b2-0ca9a3857c1b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/MarketableSecuritiesScheduleofShortTermandLongTermMarketableSecuritiesDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#MarketableSecuritiesScheduleofShortTermandLongTermMarketableSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/MarketableSecuritiesScheduleofShortTermandLongTermMarketableSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_1ca0597b-bd20-481d-9931-9a1ce7a39fee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_8217e725-09bc-4b50-ba26-f91eebf7e485" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_1ca0597b-bd20-481d-9931-9a1ce7a39fee" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_8217e725-09bc-4b50-ba26-f91eebf7e485" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_f0972957-2f99-4ae3-bf36-33d9ad703db2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_1ca0597b-bd20-481d-9931-9a1ce7a39fee" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_f0972957-2f99-4ae3-bf36-33d9ad703db2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_63558d6e-b195-4b0b-b375-ec3cb93ad37b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_1ca0597b-bd20-481d-9931-9a1ce7a39fee" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_63558d6e-b195-4b0b-b375-ec3cb93ad37b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/MarketableSecuritiesScheduleofAvailableForSaleDebtSecuritiesbyContractualMaturityDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#MarketableSecuritiesScheduleofAvailableForSaleDebtSecuritiesbyContractualMaturityDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/MarketableSecuritiesScheduleofAvailableForSaleDebtSecuritiesbyContractualMaturityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_7269ae96-f106-4784-a8fe-953de860f505" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_5953d965-06d7-4594-9c68-ab03b238d92e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_7269ae96-f106-4784-a8fe-953de860f505" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_5953d965-06d7-4594-9c68-ab03b238d92e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_62c2e849-5217-4706-b5f1-7507a5eb9f39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_7269ae96-f106-4784-a8fe-953de860f505" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_62c2e849-5217-4706-b5f1-7507a5eb9f39" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/InventoryDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#InventoryDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/InventoryDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_476cf6cc-5310-4495-ad1f-3c5b8b524632" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryGross_c2fb218a-b325-4deb-8603-1195c4b39312" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_476cf6cc-5310-4495-ad1f-3c5b8b524632" xlink:to="loc_us-gaap_InventoryGross_c2fb218a-b325-4deb-8603-1195c4b39312" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryValuationReserves_257bf59f-2cf2-4c71-a050-700d544018c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryValuationReserves"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_476cf6cc-5310-4495-ad1f-3c5b8b524632" xlink:to="loc_us-gaap_InventoryValuationReserves_257bf59f-2cf2-4c71-a050-700d544018c2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.protolabs.com/role/AccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="prlb-20250930.xsd#AccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:calculationLink xlink:role="http://www.protolabs.com/role/AccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_ae34f2f9-cb35-488c-87d4-2ef5a763e767" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_0aee2f36-0354-498f-9554-c4fee038d1cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_ae34f2f9-cb35-488c-87d4-2ef5a763e767" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_0aee2f36-0354-498f-9554-c4fee038d1cd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_6539bc2a-2f9f-4a74-9da5-6665bb78d70f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_ae34f2f9-cb35-488c-87d4-2ef5a763e767" xlink:to="loc_us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent_6539bc2a-2f9f-4a74-9da5-6665bb78d70f" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
